To the Editor:—In the Oct. 6, 1951, issue of The Journal (page 568), Hollander reports three cases of air embolism as a complication of pneumoperitoneum. In two patients the injection of air was made into the right upper quadrant of the abdomen. In the other case it is stated only that the needle was introduced into "the peritoneal cavity."This is to report two additional instances of proved air embolism due to pneumoperitoneum occurring in the course of treatment for pulmonary tuberculosis. In both patients the injection was made into the right upper quadrant. There was one fatality. Autopsy revealed air in the right auricle and right ventricle with scratch and puncture marks on the inferior surface of the liver. The other patient recovered completely from a sudden episode of hemiplegia and collapse, which occurred during the pneumoperitoneum injection. Air was aspirated from the right ventricle during the period